V-6 transmission options

Hello. I'm too sure where to post this, but since the V-6 was a factory options in the Cj's and not the flatty I'll put it here. I'm swapping out my tired old old F- head for a more spunky 225 and I'm trying to decide what transmission to bolt it to. I want to use the Spicer 18 transfer case and I want a manual. I'm thinking bout using adapting the t-90 to fit the v-6 but the more I think about it the better the low first gear of the four speed seems. I'm prolly gonna run it off road and drive it daily and maybe pull around the hay wagon. Now on to my next question did the v-6 come stock with a four speed? if so which one? I'm not sure but i remember hearing one the four speeds was weaker than the other (if I do go hog wild and hook the heavy hay wagon to it and stomp it to the floor I'd it to hold up and not grenade) so any advice would be nice thank you guys again in advance.

 

There are several 4 speed trannys that are popular conversions:

T-18
T98 (super rare)
SM420 (1950s-60s GM trucks)
SM465 (1968-91 GM trucks)

Use the search function and find out more.

Here is a good source of info as well:
http://www.novak-adapt.com/knowledge/transmission_gateway.htm

From what I've read a 4 speed tranny swap runs around $1000 when all
is said and done.

Herm the Overdrive Guy also has a good reputation here at ecj5.com.

Good luck and keep us updated !

Tim in TN

 

I'm very happy with my SM420. In a way it's more work than it looks like but it's worth the it. Some people will say go with the SM465 because it's newer and ez to get parts for, however, I can't imagine breaking my 420 so parts availibility isn't a biggie to me.

If I was starting today I would research using the T18 that can(?) be adapted to work without the (Novak or Advance) adapter. The original stock Jeep T18 is rare but worth looking for. I don't know the details of adapting a non Jeep T18 but that's where I would start my research.

 

T-18 from late76-79 was 6.32 in the wide ratio T18. I would vote for a ford dana 18 and novak adapter nice setup and easier and smaller then the sm465 (which I'm currently using on my new project. I also have a sm420 set up on the shop floor but havn't installed it yet, but it looks like more work as well.

 

I swapped a t-14 in place of the t-86aa in my 67 bolts right up. Its nicer than the t-90 because of synchro in 1st. Dont know about the strength factor

 

The T-18?

 

I am one of the lucky T-98 owners and love it. I don't know much about other transmissions but if you can't find a T-98 what about an NP 435? If I had to choose a new transmission for my Jeep I would look for the SM 420.

 

what is involved in a T 18 conversion to a V6 with d 18

 

Specifically or generally? That is a very broad question.

If you are savvy, do the research and are willing to search for parts, you can put together a swap from junkyard parts with some minor machining.

If you buy a conversion kit from Novak or Advanced, the 2WD GM 4-speeds (SM420 or SM465) will bolt up to the 225 without a lot of modification. The 2WD Ford T-18 can also be adapted, but will need more changes on the engine side.

All 4-speed swaps require the same basic things ... adapt to the engine as needed, adapt to the transfer case as needed, change the mounts, adapt the clutch linkage, modify the floors, move the cross-member, change the trans mount, change the lengths of the driveshafts, plus other minor stuff.

Search old posts and you'll find a lot of stuff on this topic.

 

Then it is a T-18 with the T-98 cast in the top. It is still a great transmission with a very adequate low first gear.

For me, 4 speeds are the only way to go. Using that low gear for creeping down steep inclines instead of using your brakes makes all the difference in the world.

Hope you find the right one you are looking for.

 

I have to agree. Since I do mostly rock crawling the low 1st gear in my SM465 is a huge help. 2 best upgrades I have done....SM465 and a Detroit Locker in the rear.